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Calculation of HV line distance relay setings
Pustowka, Pavel ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
This work is divided into practical and theoretical part. The first part deals with defective states on ehv lines, especially short-circuits and their calculation, further discusses about distance protections and the theory necessary for their correct adjustment. The second part contains practical calculation of short-circuit conditions and adjustment for distance protection on selected part of 110 kV network, belonging to EO.N company. The result of the work are values needed for adjustment all distance protection in entered part of the network.
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Short-circuit Calculation of Local Distribution Network
Byrtus, Jiří ; Paar, Martin (referee) ; Topolánek, David (advisor)
This thesis deals with transient phenomena in the electricity grid - especially with short-circuits. First part describes short-circuit types, reasons for their commencement and also consequences of their functioning. The thesis further shows waveforms of short-circuit currents and its components. A method of calculating short-circuits currents, using the constituent systems and the basic equations for calculating short-circuit impedances are also mentioned here. Relations and methods are based on valid standards of IEC 60909 – 0. The second part indicates the calculation of two-phase and three-phase short-circuit currents for specific network of industrial building. This calculation aims to verify the dimensioning of substations for short-circuit currents after connecting a synchronous generator with given power to the main substation.
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Electrical machine for wind power generator
Srna, Jan ; Chmelíček, Petr (referee) ; Kurfűrst, Jiří (advisor)
This thesis describes analyse of transient and subtransient parts of short – circuit current. Values of synchronous generator short – circuit current were measured for lower voltage and subsequently recounted to its nominal values. The analyse is useful for machines without documentation and where is measurement of needed parameters necessary. Two methods coming out of the IEEE standard were used for identification reactances and time constants and after that these methods were compared between themselves. One of the method were created in program MATLAB, where measured short – circuit currents for each phase were handled. Values of time constants are used for simple model of synchronous generator created in toolbox of program MATLAB/SIMPOWER. This simulation verifies correctness of counting transient and subtransient analyses.
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Calculation of distance protection relay setting for 110kV line.
Bartoš, Petr ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
This work deals with both the calculation of short circuit conditions of 110 kV network in the Czech Republic. This network is divided into two parts, each of which feeds a 400/110 kV substation and the calculation is performed for different locations of a short circuit. The second part deals with the calculation of distance protection settings for one part of this network. The result of this work are the values of network parameters needed to set up distance protection, which protects our individual lines of the network.
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Short Circuit Currents in DC Systems
Kolařík, Robin ; Geschwinder, Lukáš (referee) ; Paar, Martin (advisor)
The bachelor thesis deals with the analysis of short-circuit currents in DC systems. The thesis introduces the possibility of application of low voltage DC distribution in commercial and industrial buildings. The second part is focused to high voltage direct current transmission. The practical part deals with the calculation of short-circuit currents of individual elements and subsequently with short-circuit conditions in the DC network. At the end of the work are evaluated advantages and disadvantages between AC and DC voltage and suitability of use in given areas.
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Design of technical measures in LV distribution network with a high value of short-circuit currents
Šmehlík, Daniel ; Bátora, Branislav (referee) ; Ptáček, Michal (advisor)
This bachelor thesis discusses the sizing and the possibility of reducing large short circuit ratios. For a specific scheme of an industrial building, which will be fed from three transformers, the sizing will be done by means of the SICHR program. The specific objective of the technical solution is to be able to use modular circuit breakers with a ripping capability of short-circuit currents up to 10 kA in the terminal switchboards. Another objective of the work is to perform an economic evaluation of the proposed solution, or to optimize the design from the point of view of the economic aspect in meeting the technical requirements.
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Replacement of electromechanical protections in TNS Vraňany
Čechová, Karolína ; Šiler, Michal (referee) ; Orságová, Jaroslava (advisor)
The reconstruction of the traction substation Vraňany currently involves only the replacement of power oil transformers. The main reason for their replacement is the fact that the power transformers have already exceeded their designed lifecycle. According to an investor requirement, only the transformer replacement is considered, however, a new system of protection is not included. Even though the fault-free operation of power transformers is closely related to ensuring a reliable and safe electric power supply. The main aim of the thesis is to design a new system of protection for power transformers to replace the present one. In the theoretical part of the thesis is described the current state of the traction substation along with a calculation of short circuit current ratios and their comparison with the new ones considering the installation of the new power transformers. In the next part are inspected instrument current transformers if they comply with the requirements for the new protection system. The practical part of the thesis focuses on the selection of protection relay, calculation of the primary setting for selected protection functions, and subsequently conducting their functional tests. In conclusion, the economic part of the planned investment is estimated.
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Short Circuit Currents in DC Systems
Kolařík, Robin ; Geschwinder, Lukáš (referee) ; Paar, Martin (advisor)
The bachelor thesis deals with the analysis of short-circuit currents in DC systems. The thesis introduces the possibility of application of low voltage DC distribution in commercial and industrial buildings. The second part is focused to high voltage direct current transmission. The practical part deals with the calculation of short-circuit currents of individual elements and subsequently with short-circuit conditions in the DC network. At the end of the work are evaluated advantages and disadvantages between AC and DC voltage and suitability of use in given areas.
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Calculation of HV line distance relay setings
Pustowka, Pavel ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
This work is divided into practical and theoretical part. The first part deals with defective states on ehv lines, especially short-circuits and their calculation, further discusses about distance protections and the theory necessary for their correct adjustment. The second part contains practical calculation of short-circuit conditions and adjustment for distance protection on selected part of 110 kV network, belonging to EO.N company. The result of the work are values needed for adjustment all distance protection in entered part of the network.
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Calculation of short circuit currents in electtrical network
Reiter, Martin ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
First chapters of my bachelor´s thesis are focused on failures of networks, simple characteristics and description of their potential danger. Next chapters are thoroughly focused on the short-circuit, on the short-circuits graphs, on the circumstances which caused them and on their calculation. Next part is about the example, which is counted by the IEC 60909. First example is simple network. Second example is real distribution network 110kV. We are going to cogitate two involves for the real network and we are going to calculate symmetrical and asymmetrical short circuit current. There is summary of knowledge about the short-circuits and evaluation of the real distribution network at the end of my thesis.
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